I'm trying to download a file from an SQL Server table. I am using a GridView. Whenever I try to download a file, I get a corrupted file.
I am using ASP.NET and VB.NET with SQL Server 2012 Express.
Any ideas why ?
Protected Sub GridView1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles GridView1.SelectedIndexChanged
Dim ContentID = Convert.ToInt32(GridView1.SelectedRow.Cells(1).Text)
Dim ContentName = GridView1.SelectedRow.Cells(2).Text
Dim ContentType = GridView1.SelectedRow.Cells(3).Text
lblContentName.Text = "[ " + ContentName + " ]"
lblContentName.Visible = True
End Sub
Protected Sub GridView1_RowCommand(sender As Object, e As GridViewCommandEventArgs)
Dim cn As New SqlConnection("Data Source=BRIAN-PC\SQLEXPRESS;Initial Catalog=master_db;Integrated Security=True;")
If e.CommandName = "Download" Then
Dim filename As String = String.Empty
Dim id As Integer = Convert.ToInt32(e.CommandArgument)
Dim cmd As New SqlCommand("SELECT content_name,content_type,content_data FROM content WHERE content_id = " & id, cn)
cn.Open()
Dim dr As SqlDataReader = cmd.ExecuteReader
Dim bytes As Byte()
dr = cmd.ExecuteReader()
If dr.Read() Then
filename = dr("content_name").ToString()
Response.ContentType = dr("content_type").ToString()
Response.AddHeader("Content-Disposition", "attachment;filename=" & filename)
bytes = DirectCast(dr("content_file"), Byte())
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.BinaryWrite(bytes)
Response.Flush()
Response.[End]()
End If
End If
End Sub
Private Sub BindGrid()
Dim constr As String = ConfigurationManager.ConnectionStrings("ConnStringDb1").ConnectionString
Using con As New SqlConnection(constr)
Using cmd As New SqlCommand()
cmd.CommandText = "SELECT content_id, content_name FROM content"
cmd.Connection = con
con.Open()
GridView1.DataSource = cmd.ExecuteReader()
GridView1.DataBind()
con.Close()
End Using
End Using
End Sub
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not IsPostBack Then
BindGrid()
End If
End Sub
Related
I have a web form to save transactions in database and a button to display the previous action but it doesn't work although there is no error message.
Protected Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Dim nmb As Long = Convert.ToInt32(TextBox1.Text) - 1
Dim conn As New SqlConnection(ConfigurationManager.ConnectionStrings("dataConnectionString").ConnectionString)
Dim sql1 As New SqlCommand("select * from internal_trans where numbr = #numbr", conn)
sql1.Parameters.AddWithValue("#numbr", nmb)
conn.Open()
Dim adapter As New SqlDataAdapter
Dim ds As New DataSet
adapter.SelectCommand = sql1
adapter.Fill(ds)
Me.TextBox1.Text = ds.Tables(0).Rows(0).Item(0).ToString
Me.TextBox2.Text = ds.Tables(0).Rows(0).Item(1).ToString
adapter.Dispose()
sql1.Dispose()
conn.Close()
End Sub
In one of my vb page i am setting the value of a textbox through the value coming from session. In the same page i want to perform an edit operation of the record. On the page load i displayed the variables in textboxes and after editing values when i submit and take the value from the textboxes, it still take the value i set through session. It do not take the value changed in the textbox rather it shows the value assigned at the time of page load. Please help.
Here is my code,
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.SessionState.HttpSessionState
Imports System.Drawing
Imports System.Drawing.Printing
Partial Class Default2
Inherits System.Web.UI.Page
Dim cn As New SqlConnection
Dim cmd As New SqlCommand
Dim dr As SqlDataReader
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
cn = New SqlConnection("Data Source=nnn-PC;Initial Catalog=Faculty Housing;Persist Security Info=True;User ID=sa;Password=nnn;")
cn.Open()
Dim var As String
var = Session("S2").ToString()
TextBox1.Text = var
Session.Remove("S2")
cmd = New SqlCommand("select * from HouseDetails where OccupantName= '" & TextBox1.Text & "' ", cn)
dr = cmd.ExecuteReader
While (dr.Read)
Label1.Text = dr(1)
Label2.Text = dr(2)
Label3.Text = dr(3)
TextBox3.Text = dr(4)
DropDownList3.SelectedItem.Text = dr(5)
TextBox2.Text = dr(6)
TextBox4.Text = dr(7)
TextBox5.Text = dr(8)
DropDownList4.Text = dr(9)
End While
cn.Close()
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
cn = New SqlConnection("Data Source=nnn-PC;Initial Catalog=Faculty Housing;Persist Security Info=True;User ID=sa;Password=nnn;")
cn.Open()
Dim query As String = ("UPDATE HouseDetails SET OccupantName='" & TextBox1.Text & "' where HouseNum='" & Label3.Text & "'")
cmd = New SqlCommand(query, cn)
Dim x As Integer = cmd.ExecuteNonQuery()
cn.Close()
End Sub
Protected Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
End Sub
End Class
Add postback prevention with the line "If (Page.IsPostBack = false) Then", for not assigning the same value again to the textbox,
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.SessionState.HttpSessionState
Imports System.Drawing
Imports System.Drawing.Printing
Partial Class Default2
Inherits System.Web.UI.Page
Dim cn As New SqlConnection
Dim cmd As New SqlCommand
Dim dr As SqlDataReader
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If (Page.IsPostBack = false) Then
cn = New SqlConnection("Data Source=nnn-PC;Initial Catalog=Faculty Housing;Persist Security Info=True;User ID=sa;Password=nnn;")
cn.Open()
Dim var As String
var = Session("S2").ToString()
TextBox1.Text = var
Session.Remove("S2")
cmd = New SqlCommand("select * from HouseDetails where OccupantName= '" & TextBox1.Text & "' ", cn)
dr = cmd.ExecuteReader
While (dr.Read)
Label1.Text = dr(1)
Label2.Text = dr(2)
Label3.Text = dr(3)
TextBox3.Text = dr(4)
DropDownList3.SelectedItem.Text = dr(5)
TextBox2.Text = dr(6)
TextBox4.Text = dr(7)
TextBox5.Text = dr(8)
DropDownList4.Text = dr(9)
End While
cn.Close()
End If
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
cn = New SqlConnection("Data Source=nnn-PC;Initial Catalog=Faculty Housing;Persist Security Info=True;User ID=sa;Password=nnn;")
cn.Open()
Dim query As String = ("UPDATE HouseDetails SET OccupantName='" & TextBox1.Text & "' where HouseNum='" & Label3.Text & "'")
cmd = New SqlCommand(query, cn)
Dim x As Integer = cmd.ExecuteNonQuery()
cn.Close()
End Sub
Protected Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
End Sub
End Class
I fancy you're missing a check for IsPostBack to see whether or not this is a new request or a submission.
If (Not IsPostBack) Then
' populate for first load
End If
You have to put your code in IsPostback property.
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.SessionState.HttpSessionState
Imports System.Drawing
Imports System.Drawing.Printing
Partial Class Default2
Inherits System.Web.UI.Page
Dim cn As New SqlConnection
Dim cmd As New SqlCommand
Dim dr As SqlDataReader
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If (!IsPostBack) Then
cn = New SqlConnection("Data Source=nnn-PC;Initial Catalog=Faculty Housing;Persist Security Info=True;User ID=sa;Password=nnn;")
cn.Open()
Dim var As String
var = Session("S2").ToString()
TextBox1.Text = var
Session.Remove("S2")
cmd = New SqlCommand("select * from HouseDetails where OccupantName= '" & TextBox1.Text & "' ", cn)
dr = cmd.ExecuteReader
While (dr.Read)
Label1.Text = dr(1)
Label2.Text = dr(2)
Label3.Text = dr(3)
TextBox3.Text = dr(4)
DropDownList3.SelectedItem.Text = dr(5)
TextBox2.Text = dr(6)
TextBox4.Text = dr(7)
TextBox5.Text = dr(8)
DropDownList4.Text = dr(9)
End While
cn.Close()
End If
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
cn = New SqlConnection("Data Source=nnn-PC;Initial Catalog=Faculty Housing;Persist Security Info=True;User ID=sa;Password=nnn;")
cn.Open()
Dim query As String = ("UPDATE HouseDetails SET OccupantName='" & TextBox1.Text & "' where HouseNum='" & Label3.Text & "'")
cmd = New SqlCommand(query, cn)
Dim x As Integer = cmd.ExecuteNonQuery()
cn.Close()
End Sub
Protected Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
End Sub
End Class
I'm trying to download files from an SQL Server 2012 database using GridView. I am getting an ArgumentOutOfRangeException giving me this error:
Index was out of range. Must be non-negative and less than the size of the collection.
on:
Dim fileid As Integer = Convert.ToInt32(GridView1.DataKeys(gvrow.RowIndex).Value.ToString())
Code concerned:
Protected Sub lnkDownload_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim lnkbtn As LinkButton = TryCast(sender, LinkButton)
Dim gvrow As GridViewRow = TryCast(lnkbtn.NamingContainer, GridViewRow)
Dim fileid As Integer = Convert.ToInt32(GridView1.DataKeys(gvrow.RowIndex).Value.ToString())
Dim name As String, type As String
Dim con As New SqlConnection("Data Source=BRIAN-PC\SQLEXPRESS;Initial Catalog=master_db;Integrated Security=True;")
con.Open()
Using cmd As New SqlCommand()
cmd.CommandText = "Select content_name, content_type, content_file from content where content_id=#Id"
cmd.Parameters.AddWithValue("#Id", fileid)
cmd.Connection = con
con.Open()
Dim dt As DataTable = GetData(cmd)
If dt IsNot Nothing Then
download(dt)
End If
End Using
End Sub
Public Function GetData(ByVal cmd As SqlCommand) As DataTable
Dim dt As New DataTable
Dim strConnString As String = System.Configuration.ConfigurationManager.ConnectionStrings("ConnStringDb1").ConnectionString()
Dim con As New SqlConnection(strConnString)
Dim sda As New SqlDataAdapter
cmd.CommandType = CommandType.Text
cmd.Connection = con
Try
con.Open()
sda.SelectCommand = cmd
sda.Fill(dt)
Return dt
Catch ex As Exception
Response.Write(ex.Message)
Return Nothing
Finally
con.Close()
sda.Dispose()
con.Dispose()
End Try
End Function
Protected Sub download(ByVal dt As DataTable)
Dim bytes() As Byte = CType(dt.Rows(0)("Data"), Byte())
Response.Buffer = True
Response.Charset = ""
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ContentType = dt.Rows(0)("ContentType").ToString()
Response.AddHeader("content-disposition", "attachment;filename=" & dt.Rows(0)("Name").ToString())
Response.BinaryWrite(bytes)
Response.Flush()
Response.End()
End Sub
gvrow.RowIndex at time of debugging is 0.
Full Code:
Imports System.Data.SqlClient
Imports System.Data
Imports System.IO
Partial Class Documents
Inherits System.Web.UI.Page
Protected Sub btnUploadContent_Click(sender As Object, e As EventArgs) Handles btnUploadContent.Click
Dim filePath As String = FileUpload.PostedFile.FileName
Dim filename As String = Path.GetFileName(filePath)
Dim ext As String = Path.GetExtension(filename)
Dim contenttype As String = String.Empty
Select Case ext
Case ".doc"
contenttype = "application/vnd.ms-word"
Exit Select
Case ".docx"
contenttype = "application/vnd.ms-word"
Exit Select
Case ".xls"
contenttype = "application/vnd.ms-excel"
Exit Select
Case ".xlsx"
contenttype = "application/vnd.ms-excel"
Exit Select
Case ".jpg"
contenttype = "image/jpg"
Exit Select
Case ".png"
contenttype = "image/png"
Exit Select
Case ".gif"
contenttype = "image/gif"
Exit Select
Case ".pdf"
contenttype = "application/pdf"
Exit Select
End Select
If contenttype <> String.Empty Then
Dim fs As Stream = FileUpload.PostedFile.InputStream
Dim br As New BinaryReader(fs)
Dim bytes As Byte() = br.ReadBytes(fs.Length)
'insert the file into database
Dim strQuery As String = "INSERT INTO [master_db].[dbo].[content] ([content_name],[content_type],[content_file]) VALUES (#Name, #ContentType, #Data)"
Dim cmd As New SqlCommand(strQuery)
cmd.Parameters.Add("#Name", SqlDbType.VarChar).Value = filename
cmd.Parameters.Add("#ContentType", SqlDbType.VarChar).Value() = contenttype
cmd.Parameters.Add("#Data", SqlDbType.Binary).Value = bytes
InsertUpdateData(cmd)
lblMessage.ForeColor = System.Drawing.Color.Green
lblMessage.Text = "File Uploaded Successfully"
Else
lblMessage.ForeColor = System.Drawing.Color.Red
lblMessage.Text = "File format not recognised." + " Upload Image/Word/PDF/Excel formats"
End If
End Sub
Protected Sub lnkDownload_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim lnkbtn As LinkButton = TryCast(sender, LinkButton)
Dim gvrow As GridViewRow = TryCast(lnkbtn.NamingContainer, GridViewRow)
Dim fileid As Integer = Convert.ToInt32(GridView1.DataKeys(gvrow.RowIndex).Value.ToString())
Dim name As String, type As String
Dim con As New SqlConnection("Data Source=BRIAN-PC\SQLEXPRESS;Initial Catalog=master_db;Integrated Security=True;")
con.Open()
Using cmd As New SqlCommand()
cmd.CommandText = "Select content_name, content_type, content_file from content where content_id=#Id"
cmd.Parameters.AddWithValue("#Id", fileid)
cmd.Connection = con
con.Open()
Dim dt As DataTable = GetData(cmd)
If dt IsNot Nothing Then
download(dt)
End If
End Using
End Sub
Public Function GetData(ByVal cmd As SqlCommand) As DataTable
Dim dt As New DataTable
Dim strConnString As String = System.Configuration.ConfigurationManager.ConnectionStrings("ConnStringDb1").ConnectionString()
Dim con As New SqlConnection(strConnString)
Dim sda As New SqlDataAdapter
cmd.CommandType = CommandType.Text
cmd.Connection = con
Try
con.Open()
sda.SelectCommand = cmd
sda.Fill(dt)
Return dt
Catch ex As Exception
Response.Write(ex.Message)
Return Nothing
Finally
con.Close()
sda.Dispose()
con.Dispose()
End Try
End Function
Protected Sub download(ByVal dt As DataTable)
Dim bytes() As Byte = CType(dt.Rows(0)("Data"), Byte())
Response.Buffer = True
Response.Charset = ""
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ContentType = dt.Rows(0)("ContentType").ToString()
Response.AddHeader("content-disposition", "attachment;filename=" & dt.Rows(0)("Name").ToString())
Response.BinaryWrite(bytes)
Response.Flush()
Response.End()
End Sub
Public Function InsertUpdateData(ByVal cmd As SqlCommand) As Boolean
Dim strConnString As String = System.Configuration.ConfigurationManager.ConnectionStrings("ConnStringDb1").ConnectionString()
Dim conn As New SqlConnection("Data Source=BRIAN-PC\SQLEXPRESS;Initial Catalog=master_db;Integrated Security=True;")
cmd.CommandType = CommandType.Text
cmd.Connection = conn
Try
conn.Open()
cmd.ExecuteNonQuery()
Return True
Catch ex As Exception
Response.Write(ex.Message)
Return False
Finally
conn.Close()
conn.Dispose()
End Try
End Function
End Class
What is happening and why?
replace the error line with this:
Dim selectedRow As Integer = Me.GridView1.CurrentRow.Index
Dim fileid As Integer = Convert.ToInt32(Me.GridView1.Item(1,gvrow.RowIndex).Value.ToString())
Replace the number 1 with the index of the cell that contains the fileid (ie if its the 0 for the first cell, 1 for the second and so on)
Let me know if this works. Am a C# developer so conversions may differ.
pass the RowIndex via CommandArgument and use it to retrieve the DataKey value
add the below line on Button
CommandArgument='<%# DataBinder.Eval(Container, "RowIndex") %>'
and add the below line on Server Event
Dim Index As Integer = Integer.Parse(e.CommandArgument.ToString())
Dim val As String = DirectCast(Me.grid.DataKeys(Index)("YourDataKeyName"), String)
Update:
See this samples :
sample1
sample 2
I ran into this a while ago myself replacing a predecessors data adapter's with data readers for obvious reasons.
My fix was simple:
if (dt.Rows.Count == 0)
//do stuff
else
//do nothing
GV.DataSource = new DataTable();
you're also loading with a datatable, so that should make deploying it easier.
The reason in your specific case is the exception is thrown when no data is passed to the GV.
How I can upload and save image in ASP.net using with vb Language and SQL server 2008.
You can go with this tutorial.
A part from the link to save images in database:
Private Sub Button2_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button2.Click
If TextBox1.Text = "" Then
MsgBox("Fill the Name Field")
Else
Dim sql As String = "INSERT INTO Information VALUES(#name,#photo)"
Dim cmd As New SqlCommand(sql, con)
cmd.Parameters.AddWithValue("#name", TextBox1.Text)
Dim ms As New MemoryStream()
PictureBox1.BackgroundImage.Save(ms, PictureBox1.BackgroundImage.RawFormat)
Dim data As Byte() = ms.GetBuffer()
Dim p As New SqlParameter("#photo", SqlDbType.Image)
p.Value = data
cmd.Parameters.Add(p)
cmd.ExecuteNonQuery()
MessageBox.Show("Name & Image has been saved", "Save", MessageBoxButtons.OK)
Label1.Visible = False
TextBox1.Visible = False
End If
End Sub
and here is how images retrieves:
Private Sub DataGridView1_CellMouseClick(ByVal sender As Object, ByVal e As _
System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseClick
cmd = New SqlCommand("select photo from Information where name='" & _
DataGridView1.CurrentRow.Cells(0).Value() & "'", con)
Dim imageData As Byte() = DirectCast(cmd.ExecuteScalar(), Byte())
If Not imageData Is Nothing Then
Using ms As New MemoryStream(imageData, 0, imageData.Length)
ms.Write(imageData, 0, imageData.Length)
PictureBox1.BackgroundImage = Image.FromStream(ms, True)
End Using
End If
GroupBox2.SendToBack()
GroupBox2.Visible = False
Label1.Visible = True
Label1.Text = DataGridView1.CurrentRow.Cells(0).Value()
End Sub
Compare your findings with this sample and explore what you are missing.
What is the problem in my this code?
The code is working fine but when i enter new record in table and refresh the page then the changes will not be reflected...
what was the problem iam confused..
Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
Dim ds As New DataSet()
Dim connStr As String = "Data Source=DOBRIYAL-PC;Initial Catalog=MenuDb;Integrated Security=True"
Using conn As New SqlConnection(connStr)
Dim sql As String = "Select MenuID, Text, Description, ParentID from Menu"
Dim da As New SqlDataAdapter(sql, conn)
da.Fill(ds)
da.Dispose()
da.AcceptChangesDuringFill = True
End Using
ds.DataSetName = "Menus"
ds.Tables(0).TableName = "Menu"
ds.GetChanges()
Dim relation As New DataRelation("ParentChild", ds.Tables("Menu").Columns("MenuID"), ds.Tables("Menu").Columns("ParentID"), True)
relation.Nested = True
ds.Relations.Add(relation)
XmlDataSource1.Data = ds.GetXml()
If Request.Params("Sel") IsNot Nothing Then
Page.Controls.Add(New System.Web.UI.LiteralControl("You selected " + Request.Params("Sel")))
End If
XmlDataSource1.DataBind()
RadMenu1.DataBind()
End Sub
I have refatored your source code now you should see your new records on page load
Private Sub BindData()
Dim ds As New DataSet()
Dim connStr As String = "Data Source=DOBRIYAL-PC;Initial Catalog=MenuDb;Integrated Security=True"
Using conn As New SqlConnection(connStr)
Dim sql As String = "Select MenuID, Text, Description, ParentID from Menu"
Dim da As New SqlDataAdapter(sql, conn)
da.Fill(ds)
da.Dispose()
da.AcceptChangesDuringFill = True
End Using
ds.DataSetName = "Menus"
ds.Tables(0).TableName = "Menu"
ds.GetChanges()
Dim relation As New DataRelation("ParentChild", ds.Tables("Menu").Columns("MenuID"), ds.Tables("Menu").Columns("ParentID"), True)
relation.Nested = True
ds.Relations.Add(relation)
XmlDataSource1.Data = ds.GetXml()
If Request.Params("Sel") IsNot Nothing Then
Page.Controls.Add(New System.Web.UI.LiteralControl("You selected " + Request.Params("Sel")))
End If
XmlDataSource1.DataBind()
RadMenu1.DataBind()
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Me.BindData()
End Sub